1z0-076 Exam Dumps - Oracle Database 19c: Data Guard Administration

The DBMS_COMPARISON package, used for comparing and converging data objects within a single database or between databases, requires that the databases involved in the block comparison be at least mounted (A). This allows the procedure to access the data blocks for comparison. Additionally, the progress of long-running operations such as block comparison can be monitored using the dynamic performance view V$SESSION_LONGOPS (D), which provides information on the operation's progress and estimated completion time.

References:Oracle Database PL/SQL Packages and Types Reference provides comprehensive details on the DBMS_COMPARISON package, including its procedures and how to monitor their progress. Additionally, Oracle Database Reference explains the V$SESSION_LONGOPS view, which is commonly used for monitoring long operations in the database.

After a successful failover to the 'cats' database in a Data Guard configuration:

• B: Sheep, being another standby database, would typically remain in the enabled state unless specifically disabled or if there was a configuration issue.
• D: Dogs, which was the primary database prior to failover, will be in a disabled state as part of the failover process. Manual intervention is required to re-establish 'dogs' as a standby database or to return it to the primary role through another role transition.
• E: If the configuration was in Maximum Availability mode before failover, it would remain in this mode after failover, provided all settings were properly configured and no changes were made to the protection mode.

Option A is incorrect because failover does not automatically change the protection mode to Maximum Performance. The protection mode remains as it was prior to the failover unless manually altered.

References: The behavior of Oracle Data Guard during failover and the resulting configuration state is described in the Oracle Data Guard Broker documentation.

• DB_NAME (A): The name of the database, which should remain consistent across the primary and standby databases.
• db_file_name_convert (C): This parameter helps define the mapping of data file names from the primary to the standby database, which is crucial during the creation and operation of a standby database.
• COMPATIBLE (D): The compatibility level can influence the features that can be used on the standby database and must be consistent with or higher than that of the primary database, especially after upgrades.
• STANDBY_ARCHIVE_DEST (F): This parameter specifies the destination of archived redo log files on the standby database, which is important for log transport and apply services.

References:

• Oracle Data Guard Concepts and Administration Guide
• Oracle Database Reference

When enabling fast-start failover, certain conditions must be met:

• The fastStartFailoverTarget property is not set on Dogs (A): The primary database (Dogs) needs to have a fast-start failover target configured for the operation to succeed.
• The LogXptMode property is set to ASYNC on Sheep while Sheep is the target standby database (B): Fast-start failover requires synchronous redo transport (SYNC or FASTSYNC) to ensure zero data loss, which is a prerequisite for enabling the feature.
• The LogXptMode property is set to ASYNC on Dogs (D): Similar to the previous point, the primary database must be configured to use synchronous redo transport for the fast-start failover to be possible.References:
• Oracle Data Guard Broker documentation
• Oracle Database Error Messages Guide

The rate of SQL apply on a logical standby database can be influenced by:

• A: The number of PREPARER processes (which seems to be a typographical error and should read as PREPARER or similar) which prepare the redo data for the applier processes.
• B: The number of coordinator processes on the standby database instance which coordinate the SQL apply activities.
• C: The number of full table scans performed by SQL apply since full table scans can be resource-intensive and slow down the apply rate.
• E: The number of applier processes which apply the redo data to the logical standby database.

Option D is incorrect as the size of the undo tablespace on the logical standby database is more likely to affect the SQL apply lag rather than the rate of SQL apply.

Option F is incorrect because the size of the shared pool would typically not influence the rate of SQL apply. The shared pool is more related to the caching of shared SQL and PL/SQL code and control structures.

References: Oracle's documentation on SQL Apply in Data Guard configurations discusses the factors affecting the performance of SQL Apply operations on logical standby databases.

• A static service must be registered with the local listener to enable DGMGRL to restart instances during the course of broker operations (A): For DGMGRL (Data Guard Manager Command-Line Interface) to perform instance management operations, such as restarting instances, a static service registration in the listener is required. This allows the broker to connect to the database instance even when the instance is not fully up and the dynamic service registration is not available.
• Installing the oracle-database-preinstall-19c package is NOT sufficient to set up operating system kernel parameters for Oracle Net (C): While the oracle-database-preinstall-19c package automates the setting of several kernel parameters to meet the preinstallation requirements for Oracle Database, it does not specifically tailor all settings for Oracle Net in a Data Guard configuration. Additional manual configuration may be required to optimize Oracle Net services for Data Guard operations.

References:

• Oracle Data Guard Broker documentation
• Oracle Net Services Administrator's Guide

• Stop the Observer on host1 to ensure that there are no conflicts between the instances of the Observer running on different hosts.
• Update the Data Guard Broker configuration with the new hostname for the Observer. This step is crucial to redirect the Data Guard Broker to communicate with the Observer on the new host.
• Start the Observer on host2 to resume its operations in the new environment.

Disabling and re-enabling Fast-Start Failover (steps 2 and 4) are not strictly necessary for moving the Observer to a new host. These steps would be more relevant if changes to the configuration of Fast-Start Failover itself were required, which is not the case when simply relocating the Observer.

Creating a physical standby database using RMAN active database duplication requires certain prerequisites to ensure a successful and seamless operation:

• Configure Oracle Net connectivity on the primary host to the standby database instance (A): Proper Oracle Net connectivity between the primary and standby servers is essential for communication and data transfer during the duplication process. Oracle Net services provide the network foundation for Oracle Database, Oracle Net Listener, and Oracle applications.
• Establish user equivalence for the database software owner between the primary host and standby host (B): User equivalence ensures that the user who owns the Oracle Database software on the primary server has the same privileges on the standby server. This is crucial for RMAN to perform operations on both servers without encountering permission issues.
• Startup nomount the standby database instance (C): The standby database instance needs to be started in the NOMOUNT stage before the duplication can begin. This prepares the environment for creating the control file and restoring the database without mounting it, which is a necessary step in the RMAN duplication process.References:
• Oracle Database Backup and Recovery User's Guide
• Oracle Data Guard Concepts and Administration